Power-transmitting mechanism



Get. 16, 1951 s. A. ocHs ET AL 2,571,474

POWER TRANSMITTING MECHANISM Filed July 29, 1947 4 Sheets-Sheet l LEML. 4

if y la f2 if 4, ff 924m 2 f4 J 42 fz 'UU /za i! J Q 54d f77' 7' ORNE/S Oct. 16, 1951 s. A. ocHS ET AL 2,571,474

POWER TRANSMITTING MECHANISM l Filed July 29, 1947 4 Sheets-Sheet 2 ELM.

Oct. 16, 1951 s. A. OCHS ET AL 2,571,474

POWER TRANSMITTING MECHANISM Filed July 29, 1947 4 sheets-sheet 5 E 74 7i f4@ DM D D v4|,- fgi SM JNENOTQIS. D Q d Off() gafas-bfi yf BY oct. 16, 1951 l s, A CHS ETAL 2,571,474

POWER TRANslvIwINGv MECHANISM Filed vJuly 29, 1947 4 Sheets-Sheet 4 r @n A "4" @la Www/4M Patented Oct. 16, 1951 POWER- TRAN SMITTIN G MECHAN ISM Sidney` A. Ochs and Otto E. Fishburn, Detroit, Mich., assignors to Chrysler Corporation, Highland Park, Mich .,la corporation of Delaware ApplicatirqnJuly 29, 1947, serial No. 764,410

'/Ihis invention relates'to power transmission mechanism and refers particularly to improvements providingcontrol over the movement of -the shiftable member of jaw or dental clutches -ear transmissions and to the form of clutch employed -in truck, transfer cases,'wherein, for example,v a shiftable toothed clutch member splined to a shaft or hubis operable from a neutral disengaged position to one or tvv'o engaged positions.

ItY Will-be understood,- however, that the invention is applicable to clutches employed in other situations.

A problem encountered with clutches ofthe Aforegoing type has been the tendency of the shiftable member to creep and/or Walk out of mesh when undergoingtorque, especially under coast torque conditions in low speed drive f ratios.

We :have discovered that these difficulties may, forfexamplegbe overcome anda simple and leffective control structure be obtained by providing a y split hub construction between the shaft and shiftable'clutch member, one of the hub portions being fitted tothe shaft splines and the other being loose on the shaft splines to elect a limited `relative rotation between these members which is `multiplied atthe outer teeth or splines on which ithe shiftable member is non-rotatably carried. Thus when the'shiftable clutch member is in"an engaged position and connected to only 'one of the hub sections, the relative rotation between the hub sections may be utilized to block disengagement of the shiftable member bycausing'the loose hub'section to be rotated to theV limit 1' of its lostmo'tion such-that theteethor-splines of thehub sections becomemisaligned.Y Moreover, thefarrangementmay be lmade eifective in Veither engaged position ofthe clutch member.

Accordingly, it is the general object of my in- 25 Claims. (Cl. 192-53) 2 Will of the operator when the torque is released.

A further object is to provide a clutch mechanism comprising a toothed clutch element shiftable from a neutral position into engagement with a second toothed clutch element to establish a predetermined speed ratio drive or into engagement with a third toothed clutch element to establish a diierent speed ratio drive and wherein the supporting structure for-the shiftable element in one position of engagement is adapted to prevent Walking out of meshof the shiftable element when in its other engaged position.

A further object is to provide a clutch mechanism as in the preceding object wherein disengagement of the shiftable member is blocked in either engaged position. Y I

Another object of the invention-.is to provide clutch mechanism of the above character wherein blocking of the shiftable member from disengagement occurs automatically while the shiftable clutch element is subjectto torque transmission.

Still another object is to provide clutch mechanism for an automatic transmission wherein blocking of the shiftable member to prevent selfdisengagement occurs incident to engagement of this member.

A sun further object of the invention is n pro? `vide a.clutch mechanism v,including an element :for-blocking shift of the shiftable clutch member and. means for constantly biasing the blocking ele- Yment in-blocking relation to the shiftable member.

Another object isto provide a clutch mechaf -in any of its engaged positions when subject to torque transmission. Y n c A further object is to provide a clutch mechav'nsmhaving a two-step blocking arrangement.

Itis also anobject to provide-an eicient mechl:zanismV for carrying Yout the above-objects, that is vention to'provide mechanism for controlling creep and Walking out-of-mesh ltendencies of in- `-terengage'd clutch 'members during rotation Jthereof.

-lAnother object is-toV provide anclut'ch mechanism comprising interengageable drive transmitting members Yso Aconstructed and arranged for automatically holding the same in engaged relationship when torque is being transmitted theresimple in construction and well adapted to pro- `ductionmanufacture` 45Vwill become'more apparent from --the following Other ob'jects'and advantages of our invention shift 'transmission in current use providing four speeds forward and reverse, to which our invention has been applied; jl

"Fig 2 is an enlarged cross-sectional view of :fthe kmanual selector synchromesh clutch, of Fig. l

Vthrough yet permitting disengagementat the fembodying our invention;

Figs. 3 and 4 are cross-sectional views taken similarly to that of Fig. 2 but employing a modified form of clocking means between the blocker or synchronizing control ring and the hub member;

Fig. 5 is a cross-sectional view taken at 5-5 of Figs. 2, 3, and 4 respectively;

Fig. 6 is an enlarged View in perspective of a peripheral portion of the hub structure of the clutch mechanism of Fig. 3 showing the hub sections with their teeth misaligned for effecting blocking of the shiftable member of Fig. 3;

Fig. 7 is a development of the clutch teeth and teeth or tongues of the splined connection of the clutch mechanisms of Figs. 2, 3, and 4 showing the relationship thereof under drive torque conditions in rst and second speeds forward;

Fig. 8 is a similar View as in Fig. 7 showing the relation of the teeth under coast torque condition;

Fig. 9 is a similar view as in Fig. '1 showing the relationship of the teeth under drive and coast torque conditions in third and fourth speeds forward;

Fig. 10 is a cross-sectional view through the manual selector clutch of Fig. 1 showing such clutch as exemplified in Figs. 2, 3, and 4 provided with resilient means for constantly rotatably biasing a hub section to blocking position;

Fig. 11 is a view taken at II-II of Fig. 10, the clutch sleeve being omitted and part of the hub structure being broken away, illustrating the resilient biasing means of Fig. 10;

Fig. 12 is a developed view similar to that of Fig. 7 illustrating a modified tooth arrangement;

Fig. 13 is a View of a portion of a conventional gear transfer box of an automotive truck embodying our invention;

Fig. 14 is an enlarged cross-sectional view of the clutch structure of Fig. 13;

Fig. 15 is a cross-sectional view taken at I5-I5 of Fig. 14;

Fig. 16 is a development of the clutch teeth and spline teeth of the mechanism of Fig. 15 under drive torque conditions in low; and

Fig. 17 is a similar development under coast torque conditions.

Referring to the drawings in which similar numerals refer to similar parts throughout the several views, the numeral 8 is a casing for housing the transmission of Fig. 1. Drive from any suitable source, such as an internal combustion engine through a master clutch and a fluid coupling (all not shown) is transmitted to the driving shaft Il) which has a direction of rotation (clockwise looking rearwardly of the transmission) indicated by the arrow I2 in Fig. 1, thence through the speed ratio gearing to the output shaft I4. The forward end wall I6 of the casing has a ball bearing unit I8 mounted therein which journals the shaft I0. The rear wall 20 of the casing has a ball bearing unit 22 mounted therein which journals the output shaft I4, the latter extending forwardly to pilot in a bore 24 of the shaft I0 and journal therein on the needle bearings 26, all as shown, for example, in Fig. 1.

The shaft I0 carries the main drive pinion 28 which is in constant mesh with a gear 30 which drives the lay or countershaft 32 journalled on a fixed rod 34, through an overrunning clutch A of conventional type, such that when the shaft I0 drives in the direction of the arrow I2 the clutch A will engage to clutch the gear 30 to the countershaft 32 whenever the gear 30 tends to rotate faster than the countershaft. However, when- 4 ever the gear 38 tends to rotate slower than the countershaft 32 then the clutch A will automatically release whereby the shaft I0, under certain conditions, may readily drop its speed while the countershaft 32 continues to revolve.

The countershaft 32 comprises cluster gears 36, 38, the former providing drives in first and reverse and the latter providing drive in third speed. Freely rotatable on the shaft I4 are the rst and third speed driven gears 48 and 42, respectively, in constant mesh with countershaft gears 36 and 38 respectively. The shaft I4 carries a reverse gear 44 and a reverse idler gear 46 constantly in mesh with the gear 36 is shiftably mounted for meshing with the reverse gear 44 to establish reverse drive. A gear 48 drives the transmission governor through means not shown.

A manually operable clutch mechanism K (Fig. 1) various forms of which are shown for example, in Figs. 2, 3, and 4 respectively, is located between the gears 40 and 42 and comprises a shift device, clutch sleeve, or speed control member 50 adapted to be selectively shifted manually, from a neutral position, shown in Fig. 1, either rearwardly to clutch with the set of clutch teeth 5I of the first speed gear 40 after passing between teeth 52 of a conventional conical synchronizer or blocking member or ring 53 supported by the gear 40 or else forwardly to clutch with the set of clutch teeth 54 of the third speed gear 42 after passing between the teeth 55 of a conventional conical synchronizer or blocker member or ring 56 supported by the gear 42.

A second clutch L (Fig. l) has a clutch sleeve 51 carried by a hub (not shown) splined to the shaft I4. The sleeve 51 is shiftable forwardly under power by means (not shown) at predetermined vehicle speeds to clutch with the set of clutch teeth 58 of the gear 28 to establish second speed and fourth speed respectively, as hereinafter described.

In operation of the mechanism the first speed drive is obtained by shifting the sleeve 50 rearwardly to clutch with the teeth 5I, the drive passing from shaft I0 to pinion 28 thence through gear 30 to countershaft 32 and from the latter through gears 36, 40 and sleeve 50 to the output shaft I4. The third speed ratio drive is obtained by shifting the sleeve 50 forwardly to clutch with the teeth 54, the drive passing to the countershaft 32 as before and thence through the gears 38, 42 and sleeve 58 to the shaft I4.

At predetermined vehicle speed, for instance, 6 miles per hour, when operating in rst speed ratio drive the sleeve 51 will be moved forwardly and upon release of the accelerator (not shown) will engage with the teeth 58 to establish second speed ratio drive. Similarly when operating in third speed ratio drive and a predetermined vehicle speed, for instance 12 M. P. H. the sleeve 51 may be engaged with the teeth 58 to establish fourth speed ratio drive. In each of the above instances the sleeve 51 will positively clutch the shaft I0 directly to the gear 42 and so long as drive torque is transmitted from the shaft I0 to the shaft I4 through the sleeve 51 the clutch A will overrun, it being noted in this connection that the countershaft 32 will then be rotating faster forwardly than the gear 38; also that during forward shift of the sleeve 51 the clutch is neutralized by a control sleeve 60.

Reverse speed ratio drive is obtained as above indicated by shifting the idler gear 45 rearwardly to mesh withthe gear 44, sleeve 58 being then in neutral and the drive passing to the countershaft 32 as before, and thence 'throughthe Agears 56,

46,44' to the shaft I4.`

As previously stated, under certaindrive conditions, depending "upon the transmission construction and power transmitted'thereby,'there t prises tandem coaXial hubor blocker sectionsi62.

and 64 respectively, intermediate an outer member, as the shift sleeve 50,'and an inner member, as the shaft I4, each section preferably having a connection with the shaft I4 aS-by a splined,

i. e., tongue or tooth -and groove engagement;

therewith. The internal splines, tongues, or teeth 66 of the hub section' (see Fig. 5) are preferably made to t'the splineways or grooves 69 between'the splines, tongues, orteeth 'I of the shaft I4, preferably, without backlash. The in-Ll ternal splines, tongues, or teeth I2 ofthe section Elihcwever, are purposely made slightly thinner on each side of their axes than the splines 'I9 such that the teeth 'I2 are of less thickness than the width of the splineways 68 of the shaft I4 and thus thinner than the teethv G9 of the hub section 62,- by an amount, for example, between 2/1000 to 10/1000 of an inch, preferably, about /1000 of an inch, whichvlatter figure has been found to be suitable in actual practice, so as to provide for a limited relative rotational, oscillatory or clocking movement of the hub section 54 with respect to the shaft I4 and consequently, also with respect to the hub section 52 by means of the teeth 'I2 'and splineways 68 which I may for conveniencaterm-a clocking or lost motion means.

The hub section 62 has external clutching teeth or tongues 'III circumferentially spaced by recesses or grooves 'I6 and thehub section 64 has similar l clutching teeth 'I8 and spaces I9 respectively, that is, similar in size and spacing. The teeth I4 and 'I8 are preferably aligned axially when the axes of their respective internal teeth are also aligned axially. The endslof the external hub teeth are preferably square with the axis of rotation where the hub sections substantially abut, thus providing the lateral or end faces 80 on the teeth 'I4 and similar end faces 3i 'onthe teeth 'IB which, when the hubsectionsare at the-limit of the relative rotation permitted bythe lost motion in the loose splined connection` of the hub 64, overlap to provide a blockingvmeans or shoulder, for example, the blocking shoulders 82 in Fig. 7 or the blocking means or shoulders 83 in.

Fig. 8 dependent upon the transmission setting and drive conditions.

The shift device 50 has internal clutching teeth 84 circumferentially spaced byspaces 85 which teeth are slidably interengageable with the external teeth Hand `I8 of the hubsections and provide a selective connection with these teeth 'I4 and I8, the teeth 84 lbeing in engagement with both teeth 'I4 and 'I8 When-the `device 5I! is, for example, inthe neutral fposition "of `Figure' -1 `and trings.

Y rings.

6 being disengaged with respect to 4the teeth;K 14 for 'I8 -when the vdevice 50- in-.a drive position as hereinafter described'. The opposite ends86f81 of vthe-teeth184 are preferably as. shown;v :cham- Vfered Vateach-side ofthe tooth- 'axis to provide pointed teeth for facilitating shiftingv ofthe sleeve 50s Thus the forwardends 3tof the-teeth 84 have the angular .faces 8-and=89 andthe .rear end 8l of these teeth the angular facesil and 9|. The included ang-le between these angular `faces is preferably in the order of .to facilitate easy manual shifting and blocking with. respect `to shoulders 82- and 83` aforesaid.

The clutch teeth 5I, 54- and blocker teeth` 52:,55 are Asimilarly pointed and yhave a circumferential pitchand pitchdiameter similar to -the teethof the shift sleeve 59. The blocker rings 53; 56l are also provided with internal cone-shaped :threaded surfaces 92- which are adapted-to frictionally en- Vgagecomplementary cone-shaped clutch surfaces 93 on the gears 49 and 42,2 If desired, energizing springs 94 may be provided adjacentthe blocker rings Vtolightly biasy the conewsurfaces into-engagement sothat the teeth of the blockerrings may be misaligned with respect to the sleeve teeth during asynchronous-rotation of the shafts lI 0 and I4 thereby resisting shift of thesleeve-Euinto clutching engagement.

Thel relative movement between the blocker teeth and sleeve teeth is controlled by-a-circum ferential slotor slots 95 on the blocker rings and by clocking means carried by the hublsections which engage in the slots of the blocker The slots 95 are of suflicient lengthv to enable relative clocking movement betweenthe clutch sleeve and the blocker rings such that when the shafts IIJ and I4 are -rotatinglasynchronously, the teeth of the blocker rings 53,456

will respectively be positioned inblocking rela-- tionship to the teeth 84 of therclutch sleeve-.50 and will resist clutching engagement of`l` the sleeve until approximate synchronous conditions prevail. Thus in Fig. 2, for example, we `have providedpin means 96 of which there may A-be'a plurality equally spaced circumferentially of vthe hub sections. These pins are preferably rigidly mounted in the hub section-62 and'have opposite extensions 91 land 98 which lproject into the circumferential slots of the v'blocker It will be noted that the extension'projects through aclearance opening 99 in the loose hub section 64 whichl openingwill preferably be of sufficient size to permit full relative movement between the hub sections 62, '64 `to the extent 'of the splined `connection between this section `and the shaftlli.v It will be understood that'ifa sufficient number of pins 96 be employed .to carry the torqueload transmitted between'the shafts I0' and` I4 the splined connection. between the hub section 64 and shaft I4 could be dispensed with and the hub section 64 madev a free member on the Yshaft I4, relative clocking between'the hub sections being then controlled by the pins 96 and openings 99 whichwould then be Va lost'm'otion means.

When the sleeve 5-is movedA forwardly, the teeth 84 thereof engage the pointed 'ends of the blocker teeth 55 thereby urging the blocking ring under pressure into engagement with the coneshaped clutch'surface 93 whereupon the gear 42 is synchronized with the shaft I4 (the main clutch of the vehicle is released during manual shift of the sleeve 50 to facilitate this clutching action).` The blocker ring 56 will 'then rotate "slightlyrelativeto-the whub section 62 as permated by the pin es ning. 2, toperma the sleeve teeth 84 to pass through theblocker teeth 55 and interengage with the clutch teeth 54 of. the third speed gear 42 thereby positively clutching the shaftl I4 with the drive pinion 42. i

connection that interengagement of the sleeve 50 with the clutch section 62 is maintained during synchronizing of the gear 40 and until after the clutch sleeve passes through the teeth 52 Y of the blocking ring 53 to engage with the clutch.

teeth of the gear 4 0 to establish first speed ratio drive. r

When the clutch sleeve 50 is shifted forwardly Ato establish third speed drive in the transmission of Fig. 1 by engagingthe clutch sleeve teeth 84 with the clutch teeth 54, the sleeve 50 will assume a position indicated by the dot and dash lines in Fig. 1 and shown more specifically by the position of the teeth 84 in Fig. 9 which position will be just to the left or forwardly of the line of abutment between the external teeth of the hub sections 62 and 64 such that the teeth 18 of the hub section 64 will be disengaged from drive connection with the sleeve. Similarly, when the clutch sleeve 50 is shifted rearwardly into 4engagement With the clutch teeth 5| of the first speed gear, theV clutch teeth 84 o f the 'sleeve will become disengaged from drive connection with the external teeth T4 of Athe hub section 62 such that the teeth 84 are slightly to the right, or rearwardly of they line of abutment between the external teeth of the hubl sections 62 and 64. Y

When the transmission is being driven in first speed, the torque transmitted from the clutch teeth 5I to the hub teeth 'I8 will cause the hub section 64 to be rotated relative to the xedhuh section 62 to take up the lost motion the spline connection between the hub` section 64 and the shaft I4 such that the hub teeth 'I2 will contact the side faces 99 of the splines 'Ilof the shaft I4. Assuming this lostmotion to be in the order of 5/1000 of an inch this distance will be multiplied out at the periphery of the hub section 64 in accordance with the ratio of the pitch radius of the external hub teeth to the pitch radius of the shaft splines which in the drawings are approximately 2 to 1, that is, for 5/1ooo of an inch circumferential movement of the internal teeth of the hub 64, the external teeth I8 thereof will move circumferentially .about 10/iooo of an inch so as to overlap the external teeth 14 of the fixed hub section 62, as shown in the upper half of Fig. 7, this overlap reducing the width of the splineway at the forwardend of the hub section 64 and thus providing a stop shoulder 82 or narrow neck |00 for blocking forward movement of the clutch sleeve 50. in the event there should be any tendency for the sleeve 5D to walk out of mesh with respectlto the. clutch teeth 5| of the first speed gear during torque transmission. Y

Since the Walking out of mesh `tendency, appears to predominate under coast drive conditions, the subject invention Vprovides for this contingency. Thus Fig. 8 shows that under coast ;V @aan .of @wenn .,swhgtrilfaan @verlage ping relationship occurs between the external hub teeth 14, 'I8 respectively of the hub sections 62, 64 as shown in Fig. 8 to provide the blocking shoulder 83 and neck |02 to prevent disengagement of the clutch sleeve 58 upon tendency of this member to walk out of mesh under coast torque conditions in first speed ratio drive. It will be observed that the stop shoulder in this instance is just opposite to the stop shoulder providing the blocking action under drive torque conditions.

The relationship of the parts shown in Fig. 7 will also be assumed under drive torque transmission in second speed drive ratio and the relationship of the parts in Fig. 8 will be assumed under coast torque conditions in second speed drive ratio, it being understood that at such time the clutch sleeve 51 is engaged With the clutch teeth 58 of the drive gear 28 such that second speed drive is transmitted from the shaft I0 to the gear 42, gear 38, gear 36, gear 40, sleeve 50. hub section 64, and shaft I4.

When the clutch sleeve 50 is engaged with the clutch teeth 54 to establish third speed ratio drive and the drive is from the engine to the shaft I4 through the clutch teeth 54 the clutch teeth 84 of the shift sleeve 56 will then beengaged with the teeth 14 of the hub section 62 as illustrated in Fig. 9 and drive will be transmitted through this hub section to the shaft I4. In such operation the inertia of the hub section 64 which is then disengaged from the sleeve 50 will cause it to follow instead of lead the hub section 64 such that the external teeth of these hub sections will assume a relationship as shown in Fig. 9, wherein a shoulder |03 and neck |04 is formed by the overlap between the adjacent external teeth of the hub sections to block disengaging movement of the clutch sleeve 50.

Under coast torque conditions the shaft I4 will become the driver instead of the clutch teeth 54 and inertia will again maintain the hub section 64 relatively displaced with respect to the hub section 62, as shown in Fig. 9the same as under drive torque conditions.

The same relationship will exist under drive torque and coast torque drive conditions when the transmission is established in fourth speed ratio at which time the clutch 51 is engaged with the clutch teeth 58 of the drive gear 28 such that a direct drive is then established in the transmission.

In some instances it may be desired to avoid reliance on inertia of the hub section 64 to maintain this member displaced relative to the hub section 62 to effect the blocking action in third and fourth speeds (both coast and drive torque conditions) and in such instances provision may be made as in Figs. l0 and 11 for means for constantly, rotatably speaking, biasing the hub section 64 to have the teeth 'I8 overlap the teeth 'I4 of the hub section 62. Such a means may be a resilient means such as a plurality of compression springs |56 for example, three equally spaced circumferentially of the hub sections to resiliently effect relative displacement between the two hub sections to the extent permitted by the lost motion in the connection between the hub section 64 and the shaft I4. This is best accomplished as in Fig. 11 by locating the springs |06 in a half recess |01 formed in the hub section 62 and a half recess |88 formed in the hub section 64, the ends of these half recesses overlapping so as to provide lands III), ||2 respectively providing seats for the opposite ends of the springs 32` as before, and thence through-the'gears 36,

struction and power transmitted thereby, there f.

is a tendency for the manuallyshiftableclutch K to become disengaged from its engaged position by walking out of mesh. This tendency is more evident during coast drive conditions when the transmission is in a lowV speed ratiovv drive. It is an important feature of 4`this invention to prevent the shiftable clutch member from becoming disengagedduringthe various drive conditions possible except at the will of the operator.

To effect this result the clutch K is. among other things, provided with a split hub construction intermediate the shift member 58-and shaft I4. Thus in Fig. 2, for example, the hub comprises tandem coaxial hubo'r blocker sections..62

and 54 respectively, intermediate an outer member, as the shift sleeve 50,*and an inner member, as the shaft I4, each section preferably having a connection with the shaft I4 as by a splined, i. e., tongue or tooth and groove engagement therewith. The internal splines, tongues, or teeth 88 of the hub section 82 (see Fig. 5) are preferably made to t the splineways or grooves 88 between the splines, tongues, or teeth I8 of the shaft I4, preferably, without backlash. The internal splines, tongues, or teeth I2 of the section 84 however, are purposely made slightly thinner on each side of their axes than the splines *I9 such that the teeth l2 are of less thickness than the width of the splineways 68 of the shaft I4 and thus thinner than the teeth 85 of the hub section 62, by an amount, for example, between 2/1000 to 10/1000 of an inch, preferably, about 5/1000 of an inch, which latter gure has been found to be suitable in actual practice, so as to provide for a limited relative rotational, oscillatory or clocking movement of the hub section 954v with respect to the shaft I4 and consequently, also with respect to the hub section 82 by means of the teeth 12 and splineways 88 which I may for convenience, term a clocking or lost motion means.

The hubsection 82 has external clutching teeth or tongues 'i4 circumferentially spaced by recesses or grooves 16 and the hub section 64 has similar` y clutching teeth 'I8 and spaces 'I9 respectively, that is, similar in size and spacing. The teeth 'I4 and i8 are preferably aligned axially when the axes of their respective internal teeth are also aligned axially. The ends of the external hub teeth are preferably square with the axis of rotation where the hub sections substantially abut, thus providing the lateral or end faces 8l] on the teeth 'i4 and similar end faces 8l on the teeth I8 which, when the hub sections are at the limit of the relative rotation permitted by the lost motion in the loose splined connection of the hub 84, overlap to provide a blocking meansor shoulder, for example, the blocking shoulders 82 in Fig. 7 or the blocking means orshoulders 83 in Fig. 8 dependent upon the transmission setting and drive conditions.

The shift device 59 has internal clutching teeth 84 circumferentially spaced by spaces 85 which teeth are slidably interengageable with the exe ternal teeth 14 and 18 of the hub sections and vthe hub sections.

being- Adisengaged with Y respect .to vthe teeth: 14 :or 'I8 vwhen the devicel 50 ina drive positionas of the teeth 84 are preferably, as. shown,.cham

' fered `at each side of the-tooth axis to. provide pointed teeth for facilitating shifting ofthe sleeve 58. Thus the forward ends 86 of the teeth 84 have the angular faces 88 andf89 andthe rear end 8l of these teeth the angular faces 98 and 9I. The included angle between theseangular faces is preferably in the order of 90.tofacilitate :easy manual shifting and blocking with respect Ito shoulders 82 and 83 aforesaid.`

The clutch teeth 5I, 54 and blocker teeth 52,55 are similarly pointed and have a Vcircumferential pitch and pitch diameter similar to the teeth-.of the shift sleeve 59. The blocker rings l53, 5B .are also provided with internal cone-shapedthreaded surfaces 92 which are adapted to frictionally engage complementary cone-shaped clutch surfaces 93 on the gears 48 and 42. If desired,.energizing springs 94may be -provided adjacent the blocker rings to `lightly bias the cone surfaces intoengagement so that the teeth of the blockerrings may be misaligned with respect tothe sleeve teeth during asynchronous rotation of the shafts I0 and I4 thereby resisting shift of the sleeve 50.5into clutching engagement.

The relative movement between the. blocker teeth and sleeve teeth is controlled by acircumferential slot or slots 95 on the blocker rings and by clocking means carried by the hub sections which engage in the slots of the blocker rings. The slots 95 are of sufficient lengthvto enable relative-clocking movement between the clutch sleeve and the blocker rings such `that when the shafts I0 and `I4 are rotatingl asynchronously, the teeth of the blocker rings 53,56 will respectively be positioned in blocking relationship to the teeth 84 of the clutch sleeve` 50 and will resist clutching engagement of the sleeve until approximate synchronous -conditions prevail. Thus in Fig. 2, for example, we have provided-pin means 98 of which there maybe a. plurality equally spaced circumferentially of These pins are preferably rigidly mounted in the hub section 52 and have opposite extensions 91 and 98 which project into the circumferential slots of the blocker rings. It will be noted that the extensionY projects through a clearance opening 99 in the loose hub section 64 which opening will preferably be of suicient size to permit full relative movement between the hub sections 62, 64 -to the extent yof the splined connection between this section and the shaft` I4. It will be understood that ifa sucient number of pins 98 be employed to carry the torque load transmitted between the Ashafts I0 and I4 the splined connection between the hub section 64 and shaft I4 could be dispensed Withand the hub section 64 made a free member on the Vshaft I4, relative clocking between the hub sections being then controlled by the pins 96 and openings 99 which would then be a lost m0- tion means.

When the sleeve 5i3is moved forwardly, the teeth 84 thereof engage the pointed ends of the blocker teeth 55 thereby urging the blocking ring under pressure into engagement with the coneshaped clutch surface 93 whereupon the gear 42 is synchronized with the shaft I4 (the main clutch of the vehicle is released during manual shift of the sleeve 50 to facilitate this clutching action). lThe blocker ring 56 will then rotate slightly relative to the hub section 62 as per- Amated by the pin 96 in Fig. 2, to permit the teeth 5I of the first speed gear 40 is similarly synchronously effected under control of the syn- 1 chronizing blocker ring 53, it being noted in this connection that interengagement of the sleeve 50 with the clutch section 62 is maintained during synchronizing of the gear 40 and until after the clutch sleeve passes throughthe teeth 52 of the blocking ring 53 toengage with the clutch teeth 5I of the gear 40 to establish first speed ratio drive. K

When the clutch sleeve 50 is shifted forwardly to establish third speed drive in the transmission of Fig. 1 by engaging the clutch sleeve teeth 84 with the clutch teeth 54, the sleeve 50 will assume a position indicated by the dot and dash lines in Fig. 1 and shown more specifically by the position of the teeth 84 in Fig. 9 which position will be just to the left or forwardly of the line of abutment between the external teeth of the hub sections 62 and 64 such that the teeth 18 of the hub section 64 will be disengaged Vfrom drive connection with the sleeve. Similarly, when the clutch sleeve 50 is shifted rearwardly into engagement with the clutch teeth I of the first speed gear, the clutch teeth 84 of the 4 sleeve will become disengaged from drive connection with the external teeth 14 of the hub section 62 such that the teeth 84 are slightly to the right or rearwardly of the line of abutment between the external teeth of the hubv sections 62 and 64. Y H

When the transmission is being driven in first speed, the torque transmitted from the clutch teeth 5I to the hub teeth 18 will cause the hub section 64 to be rotated relative to the xed hub` section 62 to take up the lost motion in the spline connection between the hub sectionl 64 and the shaftl I4 such that the hub teeth 12 will contact the side faces 99 of the splines 10gof the shaft I4. Assuming this lost motion to 'be in the order of 5/1000 of an inch this distance will be multiplied out at the periphery of the hub section 64 in accordance with the ratio of the pitch radius of the external hub teeth to the pitch radius of the shaft; splines which inthe drawings are approximately 2 to l, that is, for 5/1000 of an inch circumferential movement of the internal teeth of the hub 64, the external teeth 18 thereof will move circumferentially about lo/iooo of an inch so as to overlap the external teeth 14 of the fixed hub section 02, as shown in the upper half of Fig. 7, this overlap reducing the width of the splineway at the forward end of the' hub section 64 and thus providing a stop shoulder 82 or narrow neck |00 for blocking forward movement of the clutch sleeve 50 in'the event there should be any tendency for the sleeve 50 to walk out of mesh with respectto the clutch teeth 5I of the rst speed gear during torque transmission.

Since the walking out of mesh tendency appears to predominate under coast drive conditions, the subject invention provides for this contingency. Thus Fig. 8 shows that under coast torque conditions the shaft I4becomes the driver, in which event the facesA IOI of the splines 10 become engaged with Vthe adjacent faceswof the .@@thf'g .of the. 590ml) .6.4 Sm'afnLQWIQP ping relationship occurs between the external hub teeth 14, 18 respectively of the hub sections 62, 64 as shown in Fig. 8 to provide the blocking shoulder 83 and neck I02 to prevent disengagement of the clutch sleeve 50 upon tendency of this member to walk out of mesh under coast torque conditions in first speed ratio drive. It will be observed that the stop shoulder in this instance is just opposite to the stop shoulder providing the blocking action under drive torque conditions.

The relationship of the parts shown in Fig. 7 will also be assumed under drive torque transmission in second speed drive ratio and the relationship of the parts in Fig. 8 will be assumed under coast torque conditions in second speed drive ratio, it being understood that at such time the clutch sleeve 51 is engaged with the clutch teeth 58 of the drive gear 28 such that second speed drive is transmitted from the shaft I0 to the gear 42, gear 38, gear 36, gear 40, sleeve 50. hub section 64, and shaft I4.

When the clutch sleeve 50 is engaged with the clutch teeth 54 to establish third speed ratio drive and the drive is from the engine to the shaft I4 through the clutch teeth 54 the clutch teeth 84 of the shift sleeve 50 will then be engaged with the teeth 14 of the hub section 62 as illustrated in Fig. 9 and drive will be transmitted through this hub section to the shaft I4. In such operation the inertia of the hub section 64 which is then disengaged from the sleeve 50 will cause it to follow instead of lead the hub section 64 such that the external teeth of these hub sections will assume a relationship as shown in Fig. 9, wherein a shoulder |03 and neck |04 is formed by the overlap between the adjacent external teeth of the hub sections to block disengaging movement of the clutch sleeve 50.

Under coast torque conditions the shaft I4 will become the driver instead of the clutch teeth 54 and inertia will again maintain the hub section 94 relatively displaced with respect to the hub section 62, as shown in Fig. 9, the same as under drive torque conditions.

The same relationship Will exist under drive torque and coast torque drive conditions when the transmission is established in fourth speed ratio at which time the clutch 51 is engaged with the clutch teeth 58 of the drive gear 28 such that a direct drive is then established in the transmission.

In some instances it may be desired to avoid reliance on inertia of the hub section 64 to maintain this member displaced relative to the hub section 62 to effect the blocking action in third and fourth speeds (both coast and drive torque conditions) and in such instances provision may be made as in Figs. 10 and 11 for means for constantly, rotatably speaking, biasing the hub section E4 to have the teeth 18 overlap the teeth 14 of the hub section 62. Such a means may be a resilient means such as a plurality of compression springs |06 for example, three equally spaced circumferentially of the hub sections to resiliently effect relative displacement between the two hub sections to the extent permitted by the lost motion in the connection between the hub section 64 and the shaft I4. This is best accomplished as in Fig. l1 by locating the springs |06 l in a half recess I01 formed in the hub section 62 and a half recess |08 formed in the hub section 64, the ends of these half recesses overlapping so as to provide lands IIO, II2 respectively providing seats for the opposite ends of the springs 9A |05, the latter resiliently displacing the hub section 62, 64 to the relationship shown in Fig. 9. In other words, the springs |06 effect a positive or constant bias between the two hub sections to displace the teeth of one with respect to the teeth of the other and thus block rearward movement of the clutch sleeve 50.

in rst and second speeds described above, for as seen from Fig. 8 the external teeth of the hub sections 62, 64 will be in the same relationship as in Fig. 9. Under drive torque operation in rst and second speed ratio drive, the hub section 62 will effect a compression of the springs in taking up the lost motion between the internal teeth of this section and the shaft |4 to assume the position shown in Fig. '7.

It will be understood that other resilient means, for example, a torsion spring may be connected between the two hub sections to provide the result previously described with respect to the springs |06. Moreover, that the spring bias may be reversed when the normal direction of rotation of the parts are opposite to that assumed or should the conditions where blocking of a movable element so warrant.

The operation of the clutch structures shown in Figs. 3 and 4 are similar to that described with respect to the structure of Fig. 2 insofar as the feature of blocking shift of the shift sleeve 50 out of engagement is concerned. The distinctions are primarily concerned with the clocking control for the blocker rings 53, 56. Thus in Fig. 3 the clocking pins 96 of the Fig. 2 structure are omitted and clockingY between the blocker rings 53, 56 and xed hub member is provided by means of struts HB, three of which are preferably provided spaced 120 apart. These struts have radially directed lips ||8 at their opposite ends which are disposed in the slots 95 of the blocker rings 53 and 56. The struts are maintained in position by means of C springs |20. The hub section 02a has a slot |22 which is a substantial t with the strut llt` whereas the hub section 54a has a slot |24 which is of sufficient width to accommodate the permissible lost motion between two hub sections described above. It will be understood, however, that the slots |22 may be made somewhat loose with respect to the strut H5 such that the clocking action between the hub sections may be possible by a rocking movement of the struts, as shown in Fig. 6. In that event the slots |22 and |24 need not be of different size. It will also be observed that in operation of the clutch structure of Fig. 3 forward or rearward movement of the sleeve 50, as the case may be, will carry with it the strut ||6 which will engage the blocker ring in its path energizing the same for movement to blocking position.

A similar result will follow under coast torque conditionsL With regard to the clutch structure in Fig. 4, it

will be apparent that here the fixed hub 52d and the loose hub 64d each have integral tongues |25 engaging in the slots 95 of the blocking or synchronizing rings to determine the relative clocking between the synchronizing ring and the hub structure. Moreover, energizing springs |28 are provided for energizing the synchronizing rings 53 and 5G respectively. Thus the blocking or synchronizing rings are served by independent clocking control members in this arrangement. It will be observed that the clocking between the hub section 04d and the blocking ring 53 does not interfere with the clocking of the hub section relative to the shaft 4 since any relative move- 10 ment under drive and coast torque conditions will occur with the shift sleeve 50 engaged with only one of the hub sections.

Fig. l2 discloses a portion of the developed structure of Fig. '7 wherein the shape of the sleeve 50, teeth 84 are slightly modified to provide a two-step blocking arrangement that includes a positive blocking shoulder for blocking any tendency for the sleeve to become disengaged should the blocking means of Fig. '1 for any reason fail. For this purpose certain teeth 84a on the shift member 50 are formed with square ends providing end faces |30 and other teeth 84h are formed similar to those of Fig. '7 but with its side faces |32 thinned down an amount less than the permissible relative rotation between the hub sections. Thus as seen in Fig. 12 the chamfered face |34 of the tooth 04b will block forward movement of the shift sleeve by encountering the shoulder 82 formed between the teeth 14 and 18. Should for any reason the face |34 pass the shoulder 82 then the face |30 of the next tooth will abut a similar shoulder 82a between two other hub teeth, it being noted that the face |30 of the tooth |14a is set back from the face |34 of the tooth 84h. This abutment will occur before the teeth 84a and 84b become disengaged from the clutch teeth 5|. The set back of the face |30 is suilicient so as not to interfere with the synchronizing function of the faces |34 on forward movement of the shift sleeve to encounter the teeth 55 of the synchronizing ring.

Figs. 13 to 15 inclusive disclose a transfer box construction embodying our invention. As seen in these figures, the conventional transfer unit comprises a driving or input shaft 4 0 adapted to receive power from the gear transmission through a propeller shaft (not shown) connected by means of a universal co-upling (also not shown) splined to the shaft |40. One end of the shaft |40 is piloted in the end of a first output shaft |42 on needle bearings |44 and the opposite end iscarried in a ball bearing |46 mounted in the casing |48 of the transfer b oX and retained therein vby a retaining ring |50 and an adaptor |52 suitably secured to the casing |48. The shaft |42 is journalled in roller bearings |56, one of which is shown. Integral with the shaft |42 is a high speed gear |58 having on its inner end a set of internal clutch teeth |50 adapted to be engaged by a mating set of external clutch teeth |60 on an axially shiftable clutch sleeve |6| telesccped with and splined to a split hub comprising a hub section |52 fiXedly splined with respect to the shaft |40 and another hub section |04 loosely splined with respect to the shaft |40, these hub sections being maintained in position on the shaft |40 between the collar |10 and split ring |12.

The shiftable clutch sleeve |0| also includes a second set of external clutch teeth |14 which are shown in Fig. 14 engaged with a mating set of internal clutch teeth |16 on an input gear |18 journalled on needle' bearings |80 carried on the shaft |40 so as to be freely rotatable relative to and on the shaft |40. As seen in Fig. 13, the input gear |18 meshes with a gear |82 of an idler gear cluster |04 which includes a second gear that in turn meshes with the output shaft gear |58. The cluster gear |84 is suitably mounted in a casingY |88 and the gear |85 meshes with a further pinion connected to a second output shaft (not shown) in a manner shown and described in the copending application of Albert .E Kimberly, Serial No. 530,602, filed April 12,

As in the case of the split hub construction in Fig. 2, the teeth or tongues 84c of the shift sleeve |6| are a sliding fit in the grooves or recesses 16a between the teeth 14 of the hub section |62 and in the grooves or recesses 19a between the teeth 18n of the hub section |64. Moreover, the internal teeth or tongues 668L are a fit in the grooves 68a between the tongues or splines 10a of the shaft |40 while the internal teeth or tongues 12 of the hub section |64 are loose in the grooves 68,a of the shaft |40 to permit the relative rotation orlost motion between this loose hub section and the shaft and other hub section described above with respect to the construction of Fig. 2, for example.

In operation of the transfer case clutch mecha-A nism, the clutch sleeve |6| is shiftable by means (not shown) under control of the driver to any one of three positions: a neutral position wherein the clutch sleeve is disengaged from the clutch teeth |16 and clutch teeth |59; a second position where it is clutched as shown in Fig. 14 with the input gear |18 to obtain low speed drive, and aV third position where it is engaged with the clutch teeth |59 of the gear |58 to establish high speed drive. It will be understood that when low speed is established, drive is transmitted from the input shaft |40 through the loose hub section 64- to the shiftable clutch member |6| thence through the clutch teeth |14, |16 to the gear |18 and through the idler cluster |84 to the high speed gear |58 which drives the output shaft |42. The gear |56 being larger than the gear |18 and the idler gear |86 being smaller than the idler gear |82, a reduction drive is obtained between the shafts |40 and |42 when the clutch teeth |14, |16 as previously stated, are engaged for low speed drive. High speed is established by shifting the shiftable clutch member |6|to engage the clutch teeth |59, |6|) in drive, power being then transmitted directly from the input shaft |40 to the output `The. subject invention is therefore, to be construed shaft |42 through the hub sections |62, |64 to the shiftable sleeve |6| and the clutch teeth |59, |60. In order to prevent walking out of mesh of the clutch sleeve |6| during transmission of torque.,

in low speed ratio drive, the internal teeth 84" of the shift sleeve |6| are set back from the rearward end of the sleeve |6| to provide a shoulder i or end face |92 (Figs. 14, 17) which in the low speed engaged position of the sleeve |6| is just forward of the line of abutment between theadtion |64 being driven through the sleeve |6| will take up the lost motion in its splined connection with the shaft |40 and assume a position of overlap'with respect to the hub section |62, that is the teeth 10a of the loose hub section |64 will overlap the teeth 14a of the hub section |62 as shown in Fig. 16, to provide a shoulder |03a for blocking rearward movement of the sleeve |6|, the said shoulder acting as an abutment for the face |92 of the teeth 84 of the shift sleeve |6|.

Under drive torque conditions in low speed drive ratio, the shaft |40 will be the driver and hence the opposite faces of the internal teeth 128L of the hub section |64 will become engaged with the teeth 10EL of the shaft |40 as shownin Fig. 17 again producing an overlap between the teeth of the hub sections |62, |64 and providing a shoulder |96 for engaging with the teeth 84c of the sleeve i 12l Y |6| 'uponany'tendency of the clutch sleeve to become disengaged.

Itwill be understood that if desired, spring means may be -provided as in the case of the clutch structures previously described and more specifically shown in Figs. 10 and 11 to' obtain a positive relative rotation between the hub,sec tions |62, |64. y

From the above description it will be seen that we have provided novel means for blocking shifting movement of the shiftable clutch-device of clutch structures both ofthe synchromesh and blocker types and manual positivecl'dtching type and that while the particular,structuresherein described are well adapted for" carrying 'out the various objects of our invention', it will bev understood that various modicationswhanges, and substitutions may be made without departing from the spirit thereof. Itvwill also be understood thatthe various features, described above may be used alone or in combination or may be combined. in Ways other ,than those,.sliown also without departing from the. present teachings.

to include all such modifications. changes, and substitutions as may come Awithin the scope .of the following claims.

We claim:

`1. In a transmission clutch the combination of an inner member, an outer member, a first intermediate section non-rotatably .carried by said inner member and connected through interlocking, tongues and grooves with saidouter member, and a second intermediatefsection having alost motion connection with one of said sections and said innerrmember permitting a small amount of relative rotation between said sectionsv and connectible through interlocking tongues and grooves with said outer member; said outer member being shiftable,.to a position of connection with, said second section. and disconnected from said first sectionwhereby adriving relationship is established between said members through said second section; the tongues of said outer member when insaid driving relationship being adapted to become rotatably overlapping relative to the tongues of saidrst section upon torque being applied through said second section to` take up said relative rotation whereby the said overlapped portions of said tonguesof saidfirst section serve to block disengaging movement of said outer member relative to said second section.

2'. In a transmission clutch the combination of. an inner member, an outer shiftable member,

a rst'intermediate section, and a second intermediate section, said members and sections having interlockingv tongue and groove connections whereby the members andsections rotate as a. unit about a common axis, there being substantial backlash in the tongue and groove connection between said second section and said inner member but less than the width ofY a tongue whereby the tongues of one section may be positioned in blocking relation to the tongues of said shiftable member when the latter is in a shifted position `disengaged from said one section and torque is being applied between said members through the other of said sections.

3. In a transmission clutch, the combination ofY an inner member, an outer member, a first intermediate section and a second intermediate section, said sections having alignable external tongues respectively interengageable with tongues on said outer member and having internal tongues respectively interengaged with tongues onlsaid inner memberwherebytheinernbers and sections are rotatable as a unit about fa" common axis, said outer member being shiftable to selective positions engaged with one-or theY other of said sections and the internalv tongues of one of said sections being ofV less thicknessthan those of said inner member interengaged therewith to permit a limited oscillatory movement between said one section and inner member whereby the external tonguesV of said sections become misaligned to block axial movement of said outer member from a shifted position when torque is being applied from onemember tothe other.

4. In a transmission change speed mechanism for a motor vehicle having an enginerandvehicle driving wheel means, a toothed cliltc'h'l member adapted to be drivingly connected to one of said engine and wheel means, a power transmitting member adapted to be driving'ly connected to the other of said engineand wheel means, an intermediate drive transmitting member having internal tongues interengaged with tongues on said power transmitting member and having external tongues, a shiftable clutching member having tongues interengageable with the external tongues of said intermediate member and shiftable into engagementwith said toothed clutch member to establish a driving relationship between said engine and vehicle driving wheels, a second intermediate member non-rotatably carried by said power transmitting member and having tongues alignable with the external tongues of said first mentioned intermediate member, the said internal tongues being of less; thickness than the tongues of the said power transmitting member to permit a limited oscillatory movement between these members and between said intermediate lmembers whereby when said shiftable member is engaged with said toothed clutch member and torque isbeing transmitted between said toothed clutch member and said power transmitting member said alignable teeth of said intermediate members will be misaligned toblock disengaging movement of said shiftable member.

5. In a power transmitting mechanism two rotatable partseach having a set of clutch teeth; a third part adapted for selective drive relation with said two parts; a bipartite hub structure f carried by said third part intermediate said two parts and comprising juxtaposed sections;` a shift device having drive connection with said hub structure and having clutch teeth adapted for selective positioning in clutchingengagement with the clutch teeth of said two rotatableparts, said shift device being disconnected from one of said sections `when in clutching engagement with one of said two, rotatable parts; said hub sections having external tongues adapted toY be aligned when said shift device is shifted between its positions of clutching engagement and one said thirdpart intermediate seid two parte 'andYV comprising juxtaposed tandem sections; a shift device having drive connection with said hub structure and having clutch teeth adapted for selective positioning in clutching engagement with the clutch teeth of said two rotatable parts, said shift device :being directly drivingly connected to only one of said hub sections when in clutching engagement with either of said two rotatable parts; the said hub sections having external tongues adapted to be aligned to facilitate shift of said shiftable device between its said clutching positions, and one of said hub sections having a lost motion connection with said third part providing a limited predetermined krelative rotational movement between this one section and said third part whereby said alignable teeth of said hub sections may be misaligned when said shift device is in either clutched position and undergoing torque transmission to prevent disengaging shift of said shift device.

'7. In a power transmitting mechanism a pair of spaced power transmitting members each having a set of clutch teeth; a power transmitting shaft coaxial With said members having radial' tongues and grooves; a hub structure carried by said shaft and comprising juxtaposed tandem sections each having internal and external radial tongues and grooves, the internal tongues andv grooves being interengaged with the tongues and grooves of said shaft and the external tongues being alignable axially; a shift device having inoscillatory movement between this -section and" said shaft whereby the tongues of said sections maybe misaligned when the shift device is engaged with one lof said members and undergoing transmission of torque.

8. In a transmission clutch mechanism the combination comprising a shiftable toothed clutching member, a toothed drive transmitting member adapted for clutching engagement with said shiftable member, a supporting memberfor supporting said shiftable member when engaged with Ysaid drive transmitting member, a toothed; blocker member for blocking disengaging shiftr` of said shiftable member,l and spring means operable between said blocker member and supporting member for rotatably disposing said blocker member in blocking relation to said shift- L able mernberfl n 9. In a transmission clutch mechanism ythe combination comprising a shiftable toothedl clutching member, a toothed drive transmitting member adapted for clutching engagement with said shiftable member, a supporting member for supporting said shiftable member when engagedl with said vdrive transmitting member, a toothed blocker member rotatable relative to said shiftable member for blocking disengaging shift of said shiftable member, spring means operable between said blocker member and supporting member for rotatably disposing said blocker member in blocking position and means for limiting said relative rotation.

10. In a transmission clutch, the combination ofaninner member, anouter shiftable member;

an intermediate section having a set of external tongues interengageable with tongues on said shiftable member and having internal tongues interengageable with tongues on said inner member whereby said section and shiftable member are rotatable with said inner member about a common axis, said inner member having further means rotatable therewith including a second set of externa-i tongues alignable with the external tonguesof said intermediate section and interengageable with the tongues of the shiftable member upon shift of said shitfable member into engagement therewith; there being predetermined clearance less than the width of a tongue in the tongue engagement between the internal tongues of said intermediate section and the tongues of said inner member to provide for limited relative rotation between said section and said inner member and between said sets of external teeth whereby the tongues of said sets may be misaligned relative to each other to block axial Amovement of said shiftable member from a position of interengagement with the external tongues of said intermediate section and disengaged from said second set of tongues when torque is being applied from one member to the other.

l1. In a power transmission clutch mechanism the combination comprising a rotatable toothed drive transmitting member, another rotatable toothed drive transmitting member adapted to be drivingly connected with said first mentioned member, a pair of toothed sections rotatable about a common axis and having a position relative to one of said members when said members are drivingly disconnected wherein their teeth are engaged with the teeth of this one member, said sections and this one member being mounted for relative shifting and being relatively'shiftable to another position to disengage the teeth of one of said sections and this one member while retaining engagement between the teeth of the other section and this one member, and as an incident thereto to effect engagement between the teeth of the other of said members and the teeth of one of said relatively shiftable sections and member whereby to establish said driving connection between said members, and lost motion connection means operably connecting said sections to provide for limited relative oscillatory motion between said sections, said means accommodating positioning of said disengaged section in blocking relationship to said one member to block disestablishment of said driving connection when said sections and said one member are relatively shifted as aforesaid and said members are undergoing drive transmission.

12. A power transmission clutch mechanismA comprising in combination a first rotatable toothed drive transmitting member, a pair of toothed sections rotatable about a common axis, a shiftable toothed drive transmitting member mounted for toothed engagement with said toothed sections and for selective shifting into toothed engagement and disengagement with said first member for establishing and disestablishing driving therebetween, said shiftable member when disengaged from said rst member having a position providing toothed engagement with said pair of sections and when in position engaged with said iirst member being in toothed engagement with one of said pair of sections and in toothed disengagement with the other of said sections, and lost motion connection means in part carried by one of said sections operable to pro- 16 vide limited relative oscillatory motion between said sections, said means accommodating positioning of the said other section in blocking relation to said shiftable member to block disengaging shift of said shiftable member when the latter is engaged as aforesaid with said iirst member and one section and undergoing drive transmission, and said sections are substantially at the limit of their said relative oscillatory motion.

13. A power transmission clutch mechanism comprising in combination a rotatable toothed drive transmitting member, another rotatable toothed drive transmitting member adapted to be drivingly connected with said rst mentioned member, a pair of toothed sections rotatable about a common laxis and having a position relative to one of said members when said members are drivingly disconnected wherein their teeth are engaged with the teeth of this one member, said sections and this one member being mounted for relative shifting and being relatively shiftable to another position to disengage the teeth of one of said sections and this one member while retaining engagement between the teeth of the other section and this one member, and as an incident thereto to eilect engagement between the teeth of the other of said members and the teeth of one of said relatively shiftable sections and member whereby to -establish said driving connection between said members, and lost motion connection means operably interconnecting said sections to provide for limited oscillatory motion between said sections, said means accommodating positioning of said disengaged section in blocking relationship to said one member to block disestablishment of said driving connection when said sections and said one member are relatively shifted as aforesaid and said members are undergoing drive transmission.

14. A power transmission clutch mechanism comprising in combination a rotatable toothed drive transmitting member, another rotatable toothed drive transmitting member adapted to be drivingly connected with said rst mentioned member, a pair of toothed sections rotatable about a common axis and having a position relative to one of said members when said members are drivingly disconnected wherein their teeth are engaged with the teeth of this one member, said sections and this one member being mounted for relative `shifting and being relatively shiftable to another position to disengage the teeth of oneof said sections and this one member while retaining engagement between the teeth of the other section andthis one member, and as an incident thereto to effect-engagementbetween the teeth of the other of said members and the teeth of one of said relatively shiftable sections and member whereby to establish said driving connection between said members, lost motion connection means `operably connecting said sections to provide for limited relative oscillatory motion between said sections, and resilient means for bia-sing said sections to the limit of their relative oscillatory motion, said lost motion connection means accommodating positioning of said disengaged section in blocking relationship to said one member to block disestablishment of said driving connection when said sections and said one member are relatively shifted as aforesaid, and said sections are substantially atthe limit of their said relative oscillatory motion.

15. A power transmission clutch mechanism comprising in combination a rotatable toothed drive transmitting member, another rotatable toothed drive transmitting member adapted to be drivingly connected with said rst mentioned member, a pair of toothed sections rotatable about a common axis and having a position relative to one of said members when said members are drivingly disconnected wherein their teeth are engaged with the teeth of this one member, said sections and this one member being mounted Vfor relative shifting and being relatively shiftable to another position to disengage the teeth of one of said sections andrthis one member While retaining engagement between the teeth of the other section and this one member, and as an incident thereto to effect engagement between the teeth of the other of said members and the teeth of one of, said relatively shiftable sections and member whereby to establish said driving connection between said members, lost motion connection means operably connecting said sections to provide for limited relative oscillatory motion between saidsections, and spring means interposed between said sections for biasing said sections to the limit of their relative oscillatory motion, said lost motion connection means accommodating positioning of s aid disengaged section in blocking relationship to said one member to block disestablishment of saiddriving connection when said sections and said one member are relatively shifted as aforesaid, and said sections are substantially at the limit of their said relative oscillatory motion.

16. A power transmission clutch mechanism comprising in combination a rst rotatable toothed drive transmitting member, a pair of toothed sections, means supporting said sections for rotation about a common axis, one of said sections being directly rotatable with said supporting means and the other including means providing a lost motion driving connection with said supporting means, a shiftable toothed drive transmitting member mounted for toothed engagement with said toothed sections and for selective shifting into toothed engagement and disengagement with said first member for establishing and disestablishing drive therebetween, said shiftable member when disengaged from said first member having a position providing toothed engagement with said pair of sections and when in position engaged with said first member being in toothed engagement with one of said pair of sections and in toothed disengagement with the other of said sections, said lost motion connection providing for relative oscillatory motion between said sections and accommodating positioning of the said other seotion in blocking relation to said shiftable member to block disengaging shift of said shiftable member when the latter is engaged as aforesaid with said first member and one section and undergoing drive transmission and said sections are substantially at the limit of their said relative oscillatory motion.

17. A power transmission clutch mechanism comprising a rst rotatable toothed power transmitting member, a 'second rotatable toothed power transmitting member, a first rotatable toothed blocker section, a second rotatable toothed blocker section coaxial with and in juxtaposition to said first section, a shiftable toothed power transmitting member mounted for toothed engagement with said sections and selectively shift- I member when in toothed engagement with said rst member being in toothed engagement with said rst section and in toothed disengagement with said second section and when in toothed engagement with said second member being in toothed engagement with said second section and in toothed disengagement with said first section, and lost motion means operably connecting said sections to provide limited relative oscillatory motion between said sections, said lost motion means accommodating positioning of said rst blocker section in blocking relation to said shiftable member to block disengaging shift of said shiftable member when the latter is engaged as aforesaid with said second member and with said second section and undergoing power transmission and accommodating positioning of said second blocker section in blocking relation to, said shiftable member to block disengaging shift of said shiftable member v. hen the latter is engaged as aforesaid with said rst member and with said first section and undergoing power transmission.

18. In a power transmission clutch mechanism the combination comprising an inner member, an outer member, a pair of juxtaposed sections, said members and sections being coaxially arranged and supported for rotation, one of said sections being nonrotatably carried relative to one of said members, lost motion means connecting the other of said sections and one of said one member and one section to provide limited oscillatory motion between said sections and between said other section and said one member, said sections and the other member of said inner and outer members being mounted for relative shifting axially be tween selected positions corresponding .to a neutral position and a drive establishing position and having connection means directly connecting ooth said sections and said other member in said neutral position and directly connecting said Y other section and said other member while disconnecting the direct connection between said one section and said other member when in said drive position, and said one section including means for blocking relative shifting from said drive position to said neutral position when there is drive between said members.

19. In a power transmission clutch mechanism the combination comprising an inner member, an outer member, a first intermediate section i, members being mounted for relative shifting axially between selected positions corresponding to a neutral position and a drive establishing position and having connection means directly connecting both said sections and said other member in said neutral position, and directly connecting said second section and said other member while disconnecting the direct connection between said rst section and said other member when in said drive position, and said first f section including means for blocking said relative shifting from said drive position to said neutral t y position when there is drive between said mem;

bers.

the combination comprising an inner member,

20. In a power transmission clutch mechanism 19 an outer member, a first intermediate section and a second intermediate section, said members and sections being coaxially arranged and supported for rotation and said first section being substantially nonrotatably carried relative to one of said members, lost motion means interconnecting said rst and said second sections for providing said second section with limited rotation relative to said first section, said sections and the other member of said inner and outer members being mounted for relative shifting axially between selected positions corresponding to a neutral position and a drive establishing position and having connection means directly connecting both said sections and said other member in said neutral position, and directly connecting said second section and said other member while disconnecting the direct connection between said rst section and said other member when in said drive position, and said first section including means for blocking said relative shifting from said drive position to said neutral position when there is drive between said members.

21. A power transmission clutch mechanism comprising in combination a first rotatable toothed drive transmitting member, a pair of toothed sections rotatable about a common axis, a shiftable toothed drive transmitting member mounted for toothed engagement with said toothed sections and for selective shifting into toothed engagement and disengagement with said first member for establishing and disestablishing drive therebetween, said shiftable member when disengaged from said first member having a position providing toothed engagement with said pair of sections and when in position engaged with said first member being in toothed engagement with one of said pair of sections and in toothed disengagement with the other of said sections, and lost motion means comprising a lateral projection on one section interengaged with a slot in the other section and operable to provide limited relative oscillatory motion between said sections, said means accommodating positioning of the said other section in blocking relation to said shiftable member to block disengaging shift of said shiftable member when the latter is engaged as aforesaid with said first member and one section and undergoing drive transmission.

22. A power transmission clutch mechanism comprising in combination a first rotatable toothed drive transmitting member, a pair of toothed sections rotatable about a common axis, a shiftable toothed drive transmitting member mounted for toothed engagement with said toothed sections and for selective shifting into toothed engagement and disengagement with said first member for establishing and disestablishing drive therebetween, said shiftable member when disengaged from said first member having a position providing toothed engagement with said pair of sections and when in position engaged with said first member being in toothed engagement with one of said pair of sections and in toothed disengagement with the other of said sections, a toothed blocker carried by said first member intermediate said sections and said first member for controlling engagement of said shiftable member with said first member, and lost motion means comprising a lateral projection on one of said sections interengaged with a slot in the other of said sections and with a slot in said toothed blocker, operable to provide limited relative oscillatory motion between said sections and between said shiftable member and said toothed blocker whereby said toothed blocker may be rotated into blocking relation to said shiftable member to block engaging shift of said shiftable member until the relative speeds of said one member and said shiftable member are synchronous and whereby said other section may be positioned in blocking relation to said shiftable member to block disengaging shift of said shiftable member when the latter is engaged as aforesaid with said first member and one section and undergoing drive transmission.

23. A power transmission clutch mechanism comprising in combination a first rotatable toothed drive transmitting member, a pair of toothed sections rotatable about a common axis, a shiftable toothed drive transmitting member mounted for toothed engagement with said toothed sections and for selective shifting into toothed engagement and disengagement with said first member for establishing and disestablishing drive therebetween, said shiftable member when disengaged from said first member having a position providing toothed engagement with said pair of sections and when in position engaged with said first member being in toothed engagement with one of said pair of section s and in toothed disengagement with the other of said sections, lost motion connection means in part carried by one of said sections operable to provide relative limited oscillatory motion between said sections, said means accommodating positioning of the said other section in blocking relation to said shiftable member to block disengaging shift of said shiftable member when the latter is engaged as aforesaid with said first member and one section and undergoing drive transmission, the teeth of said shiftable member having beveled ends and the adjacent ends of the teeth of said sections having substantially square ends.

24. A power transmission clutch mechanism comprising in combination a first rotatable toothed drive transmitting member, a pair of toothed sections rotatable about a common axis, a shiftable toothed drive transmitting member mounted for toothed engagement with said toothed sections and for selective shifting into toothed engagementv and disengagement with said first member for establishing and disestablishing drive therebetween, said shiftable member when disengaged from said first member having a position providing toothed engagement with said pair of sections and when in position engaged with said first member being in toothed engagement with one of said pair of sections and in toothed disengagement with the other of said sections, lost motion connection means in part carried by one of said sections operable to provide relative limited oscillatory motion between said sections, said means accommodating positioning of the said other section in blocking relation to said shiftable member to block disengaging shift of said shiftable member when the latter is engaged as aforesaid with said first member and one section and undergoing drive transmission, certain teeth of said shiftable member having beveled ends and other teeth thereof having square ends set back from said beveled ends and the adjacent ends of the teeth of said sections being substantially square.

25. A power transmission clutch mechanism comprising in combination a first rotatable toothed drive transmitting member, a pair of 21 toothed sections rotatable about a common axis, a shiftable toothed drive transmitting member mounted for toothed engagement with said toothed sections and for selective shifting into toothed engagement and disengagement with said first member for establishing and disestablishing drive therebetween, said shiftable member when disengaged from said first member having a position providing toothed engagement with said pair of sections and when in position engaged with said rst member being in toothed engagement with one of said pair of sections and in toothed disengagement with the other of said sections, lost motion connection means in part carried by one of said sections operable to provide relative limited oscillatory motion between said sections, said means accommodating positioning of the said other section in blocking relation to said shiftable member to block disengaging shift of said shiftable member when the latter is engaged as aforesaid with said rst member and one section and undergoing drive transmission, the adjacent ends of the teeth of said sections being substantially square, certain teeth of said shift member having beveled ends and 22 others having square ends set back from said beveled ends and the beveled teeth of said shiftable member being of lesser thickness than the teeth thereof having the square ends.

SIDNEY A. OCHS. O'I'IO E. FISHBURN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,935,965 Wahlberg Nov. 21, 1933 1,997,056 Griswold Apr. 9, 1935 2,070,140 Peterson et al. Feb. 9, 1937 2,125,526 Trimbath Aug. 2, 1938 2,202,271 Sinclair et al May 28, 1940 2,221,897 Orr Nov. 19, 1940 2,221,899 White et al Nov. 19, 1940 2,339,969 White Jan. 25, 1944 2,393,153 Fishburn Jan. 15, 1946 2,398,407 Brownyer Apr. 16, 1946 2,429,789 Bachman Oct. 28, 1947 

